There are systems for the performance of medical procedures in which a percutaneous device is inserted into a human patient with the guidance of an X-ray image using a mechanism held adjacent to the patient by a robotic arm and the mechanism is controlled from a remote cockpit which provides shielding to the operator of the system from the radiation generated in obtaining the X-ray image. The arm has typically been attached to the patient table by a rail and removed from the rail and placed on the floor between procedures.